No. Activation is required, but registration is not. Activation is the process of ensuring that Windows on your computer is used according to the Microsoft Software License Terms. Registration is the process of entering information (such as your e‑mail address) to sign up for product support, tools and tips, and other product benefits.

Genuine Windows is a recurring process that checks your product key to ensure it's being used with the hardware it was paired with during activation. If the product key is found to be non-genuine, or not valid, it's likely that the product key is either being used on another computer or is counterfeit.

For more information about genuine Windows, go to the genuine Windows website.

Maybe. When you make a significant hardware change to your computer, such as upgrading the hard disk and memory at the same time, you might be required to activate Windows again. For more information, see Activate Windows 7 on this computer.

You make a significant hardware change to your computer, such as upgrading the hard disk and memory at the same time. If a major hardware change requires activating Windows again, you'll be notified and will have three days to activate Windows.

You reinstall Windows. In this case, you’ll have 30 days to activate Windows again.

You can't use the same Windows product key to activate Windows 7 on more computers than the Microsoft Software License Terms allow. Usually, the license terms allow the product key to be used on only one computer.

If you use your installation disc or a USB flash drive to install Windows 7 on a second computer, you'll need to buy an additional copy of the same edition of Windows 7 to obtain a new product key. For more information, see Get a new Windows 7 product key.

Activation helps verify that your copy of Windows is genuine and that it has not been used on more computers than the Microsoft Software License Terms allow. In this way, activation helps prevent software counterfeiting. With an activated copy of Windows, you’ll be able to use every feature of Windows.

No. Activation is required, but registration is not. Activation is the process of ensuring that your copy of Windows is used according to the Microsoft Software License Terms. Registration is the process of entering information (such as your e‑mail address) to sign up for product support, tools and tips, and other product benefits.

You can activate either online or by phone. To activate online you need an Internet connection. Activating by phone requires interacting with an automated phone system.

To activate Windows on this computer, do the following:

Open Windows Activation by clicking the Start button , right-clicking Computer, clicking Properties, and then clicking Activate Windows now.‌ If you are prompted for an administrator password or confirmation, type the password or provide confirmation.

You can then select the method you want to use to activate.

Note

If you chose to automatically activate Windows online when you set up your computer, automatic activation begins trying to activate your copy of Windows three days after you log on for the first time.

You can reinstall Windows on the same computer as many times as you want because activation pairs the Windows product key with information about your computer hardware. If you make a significant hardware change, you might have to activate Windows again.

You uninstall Windows on one computer and install it on another. During installation, enter the product key that came with your copy of Windows. If automatic activation fails, follow the instructions that walk you through activating Windows by phone. You will have 30 days to activate your copy of Windows.

You make a significant hardware change to your computer, such as upgrading the hard disk and memory at the same time. If a major hardware change requires activating Windows again, you will be notified and will have three days to activate your copy of Windows.

If you have to activate Windows again, you don't need to buy a new product key.

To activate Windows on this computer, do the following:

Open Windows Activation by clicking the Start button , right-clicking Computer, clicking Properties, and then clicking Activate Windows now.‌ If you are prompted for an administrator password or confirmation, type the password or provide confirmation.

If your Windows product key is not valid, if you don't have a Windows product key, or if you lost the product key that came with your copy of Windows, you'll need to buy a new one to activate Windows. For more information, go to the Microsoft website.

If you don’t activate Windows within 30 days after installation, you will not be able to use every feature of Windows. You can regain full use of your computer by activating Windows.

To activate Windows on this computer, do the following:

Open Windows Activation by clicking the Start button , right-clicking Computer, clicking Properties, and then clicking Activate Windows now.‌ If you are prompted for an administrator password or confirmation, type the password or provide confirmation.